In the U.S. Pat. No. 458,542, issued Aug. 25, 1891 to Thomas W. Welsh, and assigned to the assignee of the present application, there is shown and described a pair of pipe or hose couplings, the construction and manual operation of which is substantially the same as the hose couplings used on the rolling stock owned by the American railroads to couple the air hoses at the adjacent ends of each pair of railway vehicles in a train to form a continuous train brake pipe that extends from the locomotive to the back end of the last car in the train. Unwanted uncoupling of a pair of coupled hose couplings may occur as the result of a piece of flying ballast, or other object, striking one of the couplings with a force of such magnitude that the struck coupling is rotated relative to the other coupling a sufficient amount to cause uncoupling of the two coupled hose couplings. Such an unwanted uncoupling of the two coupled hose couplings effects a release of fluid under pressure from the train brake pipe at an emergency rate which causes an undesired emergency brake application to be effected on each vehicle in the train thereby bringing the train to a stop. Such an undesired stop increases the time for the train to travel between two terminals and, therefore, causes an increase in the cost of operating the train.
Accordingly, it is the general purpose of this invention to provide a novel hose coupling that has mounted thereon one end of a leaf spring locking member of such a configuration that the other or free end thereof is so disposed that it constitutes a stop which is shiftable by the guard arm of the other one of a pair of hose couplings out of the pathway of this guard arm on the other one of the hose couplings as the one hose coupling and the guard arm thereon are rotated toward the fully coupled position. The configuration of this stop is such that the resiliency of the leaf spring locking member, upon the pair of hose couplings reaching their fully coupled position in which the guard arm passes out of contact with the stop, shifts this stop to a position in the pathway previously traveled by the guard arm to thereby prevent unwanted uncoupling of the pair of fully coupled hose couplings until the leaf spring locking member is manually deflected to shift the stop out of the pathway of the guard arm.